Procedure GridAddColumn(StrGrid: TStringGrid; NewColumn: Integer);
Var Column: Integer;
begin
 StrGrid.ColCount := StrGrid.ColCount+1;
 For Column := StrGrid.ColCount-1 downto NewColumn do
  StrGrid.Cols[Column].Assign(StrGrid.Cols[Column-1]);
 StrGrid.Cols[NewColumn-1].Text := '';
end;

procedure AddColumn(SG : TStringGrid; AtColNumber : integer;
  ColWidth : integer = 0);
var Column : integer;
  Wdth : integer;
begin
 AtColNumber := abs(AtColNumber);
 SG.ColCount := SG.ColCount + 1;
 if abs(ColWidth) = 0 then
  Wdth := SG.DefaultColWidth
 else
  Wdth := ColWidth;
 if AtColNumber <= SG.ColCount then begin
  for Column := SG.ColCount - 1 downto AtColNumber + 1 do begin
  SG.Cols[Column].Assign(SG.Cols[Column - 1]);
  SG.Colwidths[Column] := SG.Colwidths[Column - 1];
  end;
  SG.Cols[AtColNumber].Text := '';
  SG.Colwidths[AtColNumber] := Wdth;
 end;
end;